Air compressor and separator



Sept. 23, 1924. v 1,509,660

. G. M KERAHAN AIR COMPRESSOR AND SEPARATOR FileQ Aug. 13. 1923 INVENTOR; @10 1 mafm/fiw Patented Swept. 23, 1924.

PATENT OFFICE.

GEORGE MGKERAI-IAN, OF Eli-IE, PENNSYLVANIA.

AIR COMPRESSOR AND SEPARATOR.

Application filed August 13, 1923. Serial No. 657,161.

To all whom it may com-em:

Be it known that I, Gnonon MQKERAHAN, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania, have invented a new and useful Air Compressor and Separator, of which the :to-llowing is a specification.

This invention is an improvement in the rotary hydraulic air compressor for which Letters Patent No. 1,415,096 were issued to the present applicant on Feb. 13th, 1923.

In the most ellicient form of this compressor the piston-water, which is discharged with the comprest air into the receiver, is returned to the impeller wheel with the velocity resulting from the air presure in the receiver. Besides the velocity required for compressing the air. an additional delivery-speed must be given the water pistons so as to keep the compression tube clear for the succeeding charges. The usual method of utilizing the energy of this delivery-speed would be to give a tapered enlargement to the discharge end of the compression tube. But a non-expansible fluid like water does not expand to fill the enlarged area and hence the piston action ceases to be etlective. The object oi the present invention is to provide means by which this delivery-energy of the pistonwater may be recovered. This is accomplished by a novel design of separator which retains the comprest air in the re ceiver and passes the water with but slightly reduced velocity on out of the receiver to the impeller wheel. At the same time the velocity due from the air pressure in the receiver is added to the water current as the latter passes through the receiver and the water is thus returned to the impeller wheel with the combined velocities. The device will be more clearly understood when explained in connection with the accompanying; illustrations.

Fig. 1 is a sectional side elevation in which the lower part represents the air compressor and the upper part the separator. In this view the separator is shown in central section, and cover plate 12 and disk 3 sion tube.

of the compressor are removed showing the interior and piston-formers of the impeller wheel.

Fig. 2 is a section taken on the line 22 of Fig. 1. Figs. 3, 4L, 5, (3 and 7 are, respectively, sections taken on the lines 33, 4-4, 5-5, (36, and 7-7 of Fig. 1.

Like numerals refer to the same parts in all the views.

Within the bore of stationary casing 1 are the closely fitting" disks 2 and 3 which form the impeller wheel. These disks are bolted to hub 1 of shaft 5 on which. the wheel rotates in hearings 6; the hub bolts are not shown in Fig. 2. Securely fixed between disks 2 and 3 are piston-forming impellers 8 which are placed concentric with the wheel; in this case the wheel is provided with three, a full side view of which. shown in Fig. These piston-formers together with disks 2 and 3 and the bore of easing 1 form chambers in which the water pistons are molded to fit the compres- The rear ends of the chambers, with respect to the wheels rotation, are closed by the projecting part- 9, the end of which closely fits the bore of easing 1. An end view oi? the piston-forming chambers is shown at 10 in F .ig. 2. The chambers are shown rectangular in cross section but they may be made circular if desired or of any other preferred outline. The illustrations show a. centriiiugally fed air supply through the center of the wheel, the air entering through openings 11 of the disks 2 and 3, but if desired a substitute or supplementary air inlet to compression tube 17 may be located outside of stationary casing 1 and close to the compression tube entrance 18; the air in this case will be drawn into the compression tube by suction of the water pistons. Cover plate 12, bolted to casing 1, closes the latter on one side, the central parts of both casing and cover being open so as to give the air free access to openings 11. The water of which the compressing pistons are formed enters casing" 1 through nozzle 13, the water being delivered centrally between disks 2 and 3 and in the direction in which the piston-forming chambers travel. Nozzle 13 approaches casing 1 in a direction tangential to the path of the piston-forming chambers, but the nozzle is so placed'as to deliver the water in a gradual curved approach to the piston chambers so as to obviate shoclc when the water is struck by part 9 of the swiftly moving piston formers. A water piston 1 1 is shown just after being detached by the piston former; at 15 a completely formed piston is shown and 16 shows a piston passing through the compression tube 17.

The compression tube opens from casing 1 centrally and tangentially with respect to the path of the piston forming chambers. Close to casing 1 the compression tube has the same transverse form and area as the piston forming chambers but the tube may be given a small and constant reduction in area as it approaches the receiving vessel 19 thus obtaining a closer fit of the water pistons as they advance.

\Vithin receiver 19 is a curved channel 20 the open side 21 being on the radially innor side of the channels longitudinal curva' ture. The peripherally closed end 22 of this channel connects with the discharge end of compression tube 17; this connecting end of the channel has its transverse form gradually modified to the open U form which it attains at the line of section l--it.

The water pistons and comprest air enter channel 20 in alternate bodies somewhat as shown at 23 and 24. Centrifugal action of the channels longitudinal curvature will quickly cause the water to displace the air, the water forming a continuous current along the channel as shown and the air flowing out into receiver 19 through the open side 21 of the channel.

Channel 2.0 terminates in a pipe 25 of which the throat 26 has a transverse out line conforming to that of the entering water stream and a. transverse'area slightly less than that of the water stream.

Throat 26 being thus always completely filled and closed by the flowing water comprest air from receiver 19 is prevented from entering pipe 25. Below throat 26 the receiver holds a body of stored water 27 the Surface of which is in contact with the comprest air and below the surface of the water an inlet 28 places the interior of pipe 25 in communication with the stored water. The part of the water-flow in channel 20 which has been excluded by the reduced area of throat 26 will enter pipe 25 through inlet 28 and thus the whole amount of piston-water discharged through compression tube 17 will be returned to the impeller wheel.

Pipe 25 discharges into nozzle 13 which delivers the water to the impeller wheel in a direction tangential to the path of the piston-forming chambers in the manner already described. Inlet 28 would preferably slope in the direction of the water-flow in pipe 25 and the inlet need extend only part way around the pipe as indicated in the illustration. An equally satisfactory form will be to make inlet 28 a simple vertical slot in pipe 25, the slot bein of narrow width so as to reduce trictiona contact between the flowing and stored water.

In passing along curved channel 26 the water will have its velocity increased by the air pressure in receiver 19. The total acceleration due from this pressure may not be attained when the water enters pipe 25; in this case water pressure entering inlet 28 will complete the acceleration.

The invention provides special means and construction whereby the comprest air in receiver 19 is more efi'ectually prevented from entering throat 26 of pipe 25 while at the same time avoiding material subtraction from the volume and speed of the water stream. To this end channel 20 is given a U shaped cross section which has great depth in the radial direction, and is proportionately contracted in the direction perpendicular to the plane, of the channels longitudinal curvature. This U form is car ried well below throat 26 of pipe 25 the transverse form of the throat conforming on three sides to that of the channel, the three sides of the channel and the connecting sides of pipe 25 being made smoothly continuous on their interior.

The longitudinal curvature of channel 2o is carried below throat 26 in the direction of pipe 25 so that centrifugal action presses the water against the bottom and two radial sides of the pipes throat; air leakage is thus prevented at these three sides and this air tightness is made complete by the air pressure on the exposed surface of the water. There remains only the short inner side, in a radial direction, of the water stream at which air could enter throat 26.

Across this side, extending between the two long sides of the channel, is placed a separating blade or tongue 29 which forms the beginning of the fourth side of pipe 25.

The edge of this tongue which meets the intlowing water stream is disposed slightly below the surface of the water thus preventing the comprest air from entering at this side. The edge of tongue 29 will shear off a thin layer of the inflowing water as indicated in the drawing but the depth of this layer need be only small and the U shaped form of channel and throat as described will make the layer of narrow width so that the amount of water separated from the stream will not seriously impair the l11\'Ql1tl0h S eliiciency.

The separated water will join the body of stored water 27 from which an equal Ill] quantity will enter pipe 25 through inlet 28; the total quantity of water flowing through pipe 25 being limited by the area of nozzle 13.

Tongue 29 may be given a sharp knife edge as shown or any blunter form of edge thought preferable.

The tongue may be made adjustable with respect to the location of its edge below the surface of the water stream. For this adjustment an opening is provided in the wall of receiver 19 which is shown closet by a screw plug 30. If it is desired to provide for adjustment of the tongue while the compressor is in operation, obvious and simple means are available which would not require access to the interior of the receiver.

It will be understood that throat 26, at the base of tongue 29, will have an area equal to the largest requirements. The transverse area of nozzle 13 may be a little less than the area of pipe 25.

The best level for the surface of the stored water 27 will be just below the edge of tongue 29; if much higher than this it will retard the flowing water and also cause eddies which might drag the comprest air into the water current.

Inlet 28 will preferably be located as near the surface of the stored water as permissible while insuring a sufficient depth of water above the inlet as would prevent entrance of the comprest air.

It may be found advantageous to extend the longitudinal curvature of the separator so as to include inlet 28 within the curvature, the inlet being located on the radial ly inner side of pipe 25.

A. small increase in the transverse area of pipe 25 as compared with the inlet area at tongue 29 will not materially reduce the efficiency of the separator for the purpose intended.

The U form for the curved part of the separator is not essential but this form of cross section will be highly advantageous not only at throat 26 as already described but for the rest of the conduit between throat 26 and line of section 4l: l. The great radial depth thus given to the water stream will promote separation of the comprest air and water and also promote acceleration of the water flow by the air pres surein receiver 19.

In the illustration the shape of the re ceiver closely conforms to the outline of the separator, but between joints 31 and 32 the receiver may be of any form that will contain the separator and of any desired capacity. In the construction shown a oint 33 is provided so as to allow the 'curved part of the separator to be placed within the receiver. An outlet pipe 34k will convey away the comprest air. If air pipe is connected to the radially inner part of the containers longitudinal curvature then container 19 may also be used as the separating channel and channel 20 need not be used, suitable connection being made with pipe 25.

The location of water nozzle 13 with respect to the circumference of casing 1, and also of outlet 18 to the compression tube, may be varied to suit the compressor re quirements.

Below throat 26 pipe may gradually take a circular form as shown in the sec tion Fig. 7, and in this case nozzle 13 would also be of circular cross section.

l Vhile the chief purpose of the stored water 27 is to seal inlet 28 against escape of the comprest air, the water may extend down to joint 32 as shown.

'llhroughout the foregoingdescription the term water is used for the compressing fluid, but mercury or any other suitable fluid may be substituted for water and the compressor and separator may be used for compressing other gases besides air.

It will be understood that the fluid separator herein described may have other useful applications entirely apart from the air compressor with which it is associated in this specification.

By making the requisite connections this machine. may be used as a vacuum pump or exhauster.

\Vhen used for this purpose the separating channel. need not be inclosed by or form part of a compression-tight receiver and inlet 28 will not be needed, the water separated by tongue 29 being drained away and an equal quantity adn'iitted to the water circuit at any convenient point.

hat I claim as new and desire to protect by Letters Patent is:

1. In a fluid separator for use with air compressors using liquid pistons, or for other purposes, a longitudinally curved conduit into which the fluids are discharged; a receiver inclosing or forming part of said conduit; an opening or openings on the radially inner side, with respect to its longitudinal curvature, of said conduit through which the lighter fluid is delivered to the receiver; a pipe connected to the discharge end of said conduit and leading to the exterior of the inclosing receiver; a threat at the junction of said conduit and pipe, said throatbeing adapted to be always completely filled by the inflowing stream of heavier fluid and thus closed against. entrance of the lighter fluid; a body of the heavier fluid stored in the aforesaid receiver; an inlet below the surface of the stored fluid connecting this fluid with the interior of the said pipe; and a pipe leading from the receiver for conveying away the lighter fluid.

2. In a fluid separator for use with air compressors using liquid pistons, or for other purposes, a longitudinally curved conduit into which the fluids are discharged; a receiver inclosing or forming part of said conduit; an opening or openings on the radially inner side, with respect to its longitudinal curvature, of said conduit through which the lighter fluid is delivered to the receiver; a pipe connected to the discharge end of said conduit and leading to the ex terior of the inclosing receiver, the unction of said conduit and pipe partaking of the conduits longitudinal curvature; means at the entrance of said pipe on the radially inner side of the longitudinal curvature, said means being adapted to prevent the lighter fluid from entering said pipe; a body of the heavier fluid stored in the aforementioned receiver; an inlet below the surface of the stored fluid connecting this fluid with the interior of said pipe; and a pipe leading from the receiver for conveying away the lighter fluid.

3. In a fluid separator for use with air :ompressors using liquid pistons, or for other purposes, a longitudinally curved channel into which the fluids are discharged, said channel being of U shaped cross section and having its open side disposed on the radially inner side with respect to the channels longitudinal curvature; a receiver inclosing or forming part of said channel; a pipe connected to the discharge end of said channel and leading to the exterior of the inclosing receiver, the junction of said pipe and channel partaking of the channels longitudinal curvature; a separating tongue at the junction of said channel and pipe, said tongue being a projecting continuation, between the radial sides of said channel, 01 the pipe on the radially inner side of the longitudinal curvature; a body of the heavier fluid stored in the aforesaid receiver; an inlet below the surface of the stored fluid connecting this fluid with the interior of said pipe; and a pipe leading from the receiver for conveying away the lighter fluid.

4. In a compressor using liquid pistons for compressing air or other gas; in combination, a stationary casing; piston-fornr ing impellers revolving in said casing; a compression tube disposed in tangential relation to the path of the pistons thus formed; an air inlet to the said compression tube; a longitudinally curved conduit connected t the discharge end of said compression tube; a receiver inclosing or forming part of said conduit; comn'iunicating means, on its radially inner side with respect to the conduits longitudinal curvature,-bet.vecn said conduit and receiver; a pipe connected to the discharge end of said conduit, the junction of said pipe and conduit partaking of the conduits longitudinal curvature; means at the entrance of said pipe on the radially inner side of the longitudinal curvature, said means being adapted to prevent the comprest air from entering said pipe; a body of the piston-liquid stored in the aforesaid receiver; an inlet below the surface of the stored liquid connecting this liquid with the interior of the aforesaid pipe: a nozzle entering the atorw mentioned stationary casing, said nozzle being adapted to deliver the piston-liquid to the path of the atorementioncd pistont'orming impellers and in the direction of the latters travel, and the said nozzle connected to the said pipe; and a pipe leading from the receiver for conveying away the comprest air or other gas.

5. In a compressor using liquid pistons for compressing air or other gas; in combination, a stationary casing; a conq'ircssion tube leading tangentially from the circumferential interior of said casing; revolving impellers in said casing adapted to form the liquid into pistons to fit the said compression tube; an air inlet to the compression tube; a longitudinally curved channel of U shaped cross section connected to the discharge end of said compression tube; a receiver inclosing or torn'iing part of said channel; a pipe connected to the discharge end of said channel; a separating tongue, at the junction of said pipe and channel, on the radially inner side with respect to the longitudinal curvature; a body of piston-liquid stored in the aforesaid receiver; an inlet below the surface of the stored liquid connecting this liquid with the interior ot the atoresaid pipe; a nozzle delivering piston-liquid to the :1fOlOllltlltlUllOtl piston-forming lll'lPOllGlfS, said nozzle con nceted to the discharge end of said pipe; and a pipe leading from the receiver for conveying away the comprest air or other gas.

6. In a compressor using liquid pistons for compressing air or other gas: in combi nation, a pump; a longitudinally curved conduit into which the fluids are discharged; a receiver inclosing or forming part of said conduit; connnunicating means, on the condnits radially inner side with respect to the longitudinal curvature, between said conduit and said receiver; a pipe connected to the discharge end of said conduit; a throat at the junction of said pipe and conduit, said throat being adapted to be always completely filled by the inflowing stream of liquid and thus closed against the entrance of the comprest air: a body ot the piston-liquid stored in the aforesaid receiver: an inlet below the surface of the stored liquid connecting the liquid with the interior of the aforesaid pipe; a nozzle connected to the discharge end of said pipe for delivering piston-liquid to the afi rementioned pump; and a pipe for conveying comprest air from the receiver.

7. In a vacuum or exhaust pump using 5 liquid pistons; in combination, a pump; a

longitudinally curved conduit connected to the discharge of said pump; a pipe connected to the discharge end of said conduit;

a throat at the junction of pipe and conduit, said throat being adapted to he al ways completely filled by the intlowing liquid and thus closed against entrance of the gaseous fluid and the discharge end of the aforesaid pipe connected to an inlet of the pump; and means on the radially inner side of the conduits longitudinal curvature for conveying away the gaseous fluid.

GEORGE MoKERAI-IAN. 

